The present invention relates to the use of thiram as an inhibitor of angiogenesis and/or inflammation for the preparation of pharmaceutical compositions useful for the treatment of angiogenesis-dependent disorders and/or inflammation associated with a disease or disorder, and to methods of treatment of said disorders.
Tetramethylthioperoxydicarbonic diamide or tetramethylthiurarn disulfide, hereinafter thiram, is a fungicidal and bactericidal agent used as antiseptic, seed disinfectant and animal repellent. It is also used in the rubber processing industry as rubber accelerator and vulcanizer. Thiram has an ampiphilic nature, is soluble in water but it solubilizes better in hydrophobic solutions such as methanol, acetone or chloroform.
Thiram was shown to inhibit various enzymes in vitro such as yeast glutathione reductase (Elskens, 1995) and horse liver mitochondrial aldehyde dehydrogenase (Sanny, 1987), and in vivo such as lipoprotein lipase activity in adipose tissue (Sadurska, 1993), aldehyde dehydrogenase and aldehyde oxidase (Freundt, 1977) in rats.
Thiram was shown to be toxic to human lymphocytes in vitro in the presence of the S-9 mix (Perocco, 1989). Thiram was also shown to reduce the incidence of spontaneous leukemia and of pituitary and thyroid tumors in rats treated for two years (0.05-0.1% in the diet), without being carcinogenic (Takahashi, 1983; Hasegawa, 1988). Female rats treated with 40 mg/Kg/day for 2 years with thiram had decreased spontaneous occurrences of mammary fibroadenoma (Maita, 1991). Thiram also decreased the formation of N-nitrosodiethylamine-induced hepatomas in rats (Klimova, 1990).
Thiram was shown to be non-clastogenic (100-200 mg/Kg) and non-carcinogenic in the skin (1 mg) in male Swiss albino mice (George, 1995).
None of the above publications describes or suggests the use of thiram as an inhibitor of angiogenesis and/or of inflammation.
It has now been found in accordance with the present invention that thiram inhibits angiogenesis and is able to block neovascularization induced subcutaneously in nude mice. It has further been found that thiram reduced inflammation in rats suffering from adjuvant arthritis.
The pharmaceutical composition of the invention is suitable for treatment of angiogenesis-dependent diseases including, but not being limited to, ophthalmologic disorders such as diabetic retinopathy, corneal graft neovascularization, neovascular glaucoma, trachoma and retinopathy of prematurity also known as retrolental fibroplasia, dermatologic disorders including dermatitis, psoriasis and pyogenic granuloma, cardiovascular disorders including atherosclerosis, pediatric disorders including hemangioma, angiofibroma, and hemophilic joints, neurologic cerebrovascular disorders including arteriovenous malformation, neoplasms including leukemia and solid tumors, connective tissue disorders including arthritis and scleroderma, autoimmune diseases and treatment of hypertrophic scars.
The solid tumors that can be treated with thiram according to the invention include, but are not limited to, bladder, breast, cervix, ear, esophagus, kidney, larynx, liver, lung, ovary, pancreas, prostate, skin, stomach, thyroid, urethra and uterus cancers.
The pharmaceutical composition of the invention is further suitable for the inhibition, alleviation or treatment of inflammatory symptoms associated with, for example, rheumatic diseases such as rheumatic fever and rheumatoid arthritis, fibrositis, myositis, neuritis, sciatica, lumbago, glomerulitis, nephritis, vasculitis, allergic diseases and autoimmune diseases.
For the preparation of the pharmaceutical compositions of the invention, thiram is mixed with pharmaceutically acceptable carriers and conventional excipients to produce unit dosage formulations suitable for administration. Any suitable mode of administration is envisaged by the invention, but oral administration is preferred.
The dosage of thiram to be administered daily will depend on the disorder being treated and the age, weight and condition of the patient being treated, and can be determined without difficulty by skilled physicians. Based on the examples herein in animals, it can be deduced that dosages between 1-50 mg/person are suitable for humans.
In another aspect, the invention relates to a method for inhibiting angiogenesis and/or inflammation in a mammal, particularly humans, which comprises administering to a mammal in need thereof an amount of thiram effective for inhibiting angiogenesis and/or inflammation.
In still another aspect, the invention relates to the use of thiram to prevent cell hyperproliferation and formation of clots along or around medical devices such as stents, catheters, cannulas, electrodes, and the like. In one embodiment, thiram may be systemically administered to a patient in which such a device has been inserted. In another embodiment, the medical device is coated with thiram before insertion in the patient, and such thiram-coated medical devices are also envisaged by the present invention.
Abbreviations: BCE: bovine capillary endothelial cells; bFGF: basic fibroblast growth factor; BSMC: bovine vascular smooth muscle cells; DMEM: Dulbecco""s Modified Eagle""s Medium; EGF: epidermal growth factor; FCS: fetal calf serum; GPS: glutamine/penicillin/streptomycin; HB-EGF: heparin-binding epidermal growth factor.